Building Reactor apps and reading diagnostics — `mur check <path>` is the build (same exit code as `dotnet build`, never re-run to confirm) with one-line diagnostics, skill pointers, and `→ try:` did-you-mean suggestions to use verbatim. Covers iteration vs `--final` workflow, the common-build-errors cheat table mapping `REACTOR_HOOKS_*` / `REACTOR_DSL_*` / `REACTOR_THEME_*` / `REACTOR_A11Y_*` / `CS*` IDs to fixes, when single-file vs `.csproj` matters for analyzer coverage, build prerequisites. Use when a build fails, you see an analyzer warning, or you want a structured diagnostic stream instead of raw MSBuild output.
Reactor charts and data visualization — choosing a chart type (line, bar, area, donut, `TreeChart`, `ForceGraph`), the chart DSL, `LabelView` / `XTickLabelView` / `YTickLabelView` for icon-plus-text and rich labels, and the visualization-best-practices rules. Use when adding charts or designing visualizations.
Reactor commanding — actions that appear in multiple surfaces (menu + toolbar), need keyboard shortcuts, or need `CanExecute`. `Command`, `StandardCommand`, `UseCommand`, `CommandHost`. Use when wiring shared actions or shortcuts.
Pointer to the full Reactor API signatures index (`references/reactor.api.txt`). The 90% of DSL content — hooks, components, common factories, modifiers, theme tokens, gotchas, React-to-Reactor mapping — already lives in `reactor-getting-started`. Load this skill only when you need to verify a less-common signature against the alphabetized full index.
Reactor essentials in one place — React-to-Reactor mental model, minimal app shape, hooks, the most-used factories, the critical gotchas, and project setup. This is the only skill you need loaded for typical Reactor work; load topical skills (`reactor-async`, `reactor-design`, etc.) only when the task explicitly calls for them.
Reactor navigation — `UseNavigation` hook, `NavigationHost` renderer, `NavigationView` sidebar, `TabView` tabs, route params, stack operations, page lifecycle, deep linking, transitions, caching. Use when building multi-page apps or wiring sidebar/tab navigation.
Reactor top-level windowing cookbook: WindowSpec, OpenWindow, draggable windows, borderless/tool windows, placement persistence, taskbar visibility, z-order, aspect ratio, SizeToContent, displays, taskbar integration, and picker HWND wiring.